An image forming apparatus, such as a printer or a copying machine, is provided with a rotating force transmitting mechanism which transmits a rotating force from a driving force to a rotating shaft of a rotating member, such as a developing roller, an agitating paddle or a photosensitive drum. In recent years, cost reduction or downsizing of the image forming apparatus has been in progress, and the rotating force transmitting mechanism also requires a measure for cost reduction or downsizing.
With reference to FIG. 13A and FIG. 13B, the prior art of the rotating force transmitting mechanism will be described. FIG. 13A shows a method using a caulking pin 101 and FIG. 13B shows a method using a plastic pin 105.
As shown in FIG. 13A, in the method using the caulking pin 101, a rotating member 103 is fitted to the caulking pin 101 erected on a base plate 102 made of a metal plate material, and the rotating member 103 is prevented from slipping off from the caulking pin 101 by a plastic slip-stop 104. In such method using the caulking pin 101, the rotating member 103 can be supported in a cantilever manner, enabling space saving. For example, the rotating members 103 can be disposed to overlap in an axial direction of the rotating shafts. Also, depending on a construction of the rotating force transmitting mechanism, it is sufficient to use only one base plate 102. However, processes of preparing the caulking pin 101 and pressing the caulking pin 101 against the base plate 102 to be fixed are required, resulting in higher costs owing to an increased number of parts or working processes.
On the other hand, as shown in FIG. 13B, in the method using the plastic pin 105 (or header pin), apertures 106a, 107a are respectively formed at opposite positions of the base plates 106, 107 oppositely disposed to each other and the plastic pin 105 to which the rotating member 108 is fitted is bridged between the apertures 106a and 106b. The method using the plastic pin 105 enables cost reduction compared with the method using the caulking pin 101 and thus is spreading in place of the method using the caulking pin 101. However, in order to prevent from slipping off of the rotating member 108, the rotating member 108 must be supported in a double-supported manner, and space saving, such as in the cantilever manner, is difficult.
On the other hand, in Patent Literature 1, there is disclosed a rotating member mounting structure in which a burring part or projection part is formed by applying several press processes to a metal plate material and then the rotating member is rotatably supported on the burring part or projection part.